Pellizzer G, Massey J T, Lurito J T, Georgopoulos A P
Brain Sciences Center, Veterans Affairs Medical Center, Minneapolis, MN 55417.
Exp Brain Res. 1992;92(2):326-37. doi: 10.1007/BF00227975.
Normal human subjects grasped an isometric handle with an unrestrained, pronated hand. They were asked to exert forces continuously to draw lemniscates (figure eights) in specified or self-chosen planes and in the presence or absence of a three-dimensional visual feedback cursor and a visual template. In every condition, the mean plane orientation in the force space differed appreciably between the two loops of the figure, as described previously by Soechting and Terzuolo (1987a) for free drawing arm movements. These findings suggest that the planar segmentation of the motor trajectory is not a consequence of joint motion but arises from central constraints related to the production of motor trajectory in space.
正常人类受试者用一只自由旋前的手握住一个等长手柄。他们被要求持续施加力，在指定平面或自行选择的平面上绘制lemniscates（数字8字形），并且在有或没有三维视觉反馈光标和视觉模板的情况下进行。在每种情况下，力空间中的平均平面方向在数字8字形的两个环之间都有明显差异，正如Soechting和Terzuolo（1987a）之前对自由绘制手臂运动所描述的那样。这些发现表明，运动轨迹的平面分割不是关节运动的结果，而是源于与空间中运动轨迹产生相关的中枢约束。
